Sulfur-containing compositions of unsaturated esters, their use as additives for lubricants and the lubricating compositions containing them

ABSTRACT

Sulfurized compositions are obtained by sulfurizing an unsaturated ester obtained by esterifying at least one aliphatic mono- or di-carboxylic acid with at least one aliphatic ethylenically unsaturated mono-hydric alcohol. They are used as additives for mineral or synthetic oils.

United States Patent 1 1 Bourdoncle et al.

l l SULFUR-CONTAINING COMPOSITIONS OF UNSATURATED ESTERS, THEIR USE AS ADDITIVES FOR LUBRICANTS AND THE LUBRICATING COMPOSITIONS CONTAINING THEM [75] Inventors: Bernard Bourdoncle. Talence;

Bernard Sillion. Grenoble. both of France [73} Assignee: Institut Francaise du Petrole, des

Carburants et Lubrifiants, Rueil-Malmaison. France I22] Filed: Oct. 29, I973 [2]] Appl. No.1 410,531

[30] Foreign Application Priority Data Nov. 3. I972 France 72.39] III Dec. I. I972 France 72.42980 [52] US. Cl 260/125; 252/486 [51] Int. Cl. CIOM 1/38; CO7G [7/00 Nov. 11, 1975 Primary Ext!tmurLewis Gotts .4.\1\'i5[1nl I;'.\um1'/it'rD. R. Phillips Attorney. igour. m Firm-Millen. Raptes & White [57] ABSTRACT Sulfurized compositions are obtained by sulfurizing an unsaturated ester obtained by esterifying at least one aliphatic mom or di-carboxylic acid with at least one aliphatic eth \lenieall v unsaturated monwhydrie alcohol. The are used as additives for mineral or syn thetic oils.

25 Claims. N0 Drawings SULFUR-CONTAINING COMPOSITIONS OF UNSATURATED ES'I'ERS, THEIR USE AS ADDITIVES FOR LUBRICANTS AND THE LUBRICATING COMPOSITIONS CONTAINING THEM The invention concerns new sulfur-containing compositions of unsaturated esters which may be used as additives for lubricants, and the lubricating compositions containing them.

It is known that the progress in the machine art tends towards still improved performances and therefore to the manufacture of more and more heavily loaded mechanisms, whose lubrication cannot be easily per formed, particularly with respect to the persistence of the oil film, due to the existence of a limit running condition for lubrication. This is particularly true in the case of heavily loaded gears and also in the field of metal working, particularly metal cutting. When the persistence of the oil film can no longer be ensured, seizing occurs, which can result in the breaking of the machine or tool.

In order to avoid the above inconveniences, it has been proposed up to now to improve the lubricity of the oil, i.e. the resistance of the oil film, particularly by adding thereto a low proportion of sulfurized spermaceti oil. However, it is known that new regulations limit or forbid cachalot fishing so that natural spermaceti oil will be soon unavailable for industrial use at a reasonable price.

The invention has for object to provide new sulfurized compositions of unsaturated esters which can be used as additives for lubricants and are able to confer to mineral and synthetic lubricating oils lubricity, antiwear and extreme-pressure properties at least equivalent to those obtained by means of sulfurized spermaceti oil.

Another object of the invention is to provide lubricity additives for lubricants, manufactured from starting materials which are easily available, cheap and not liable to become unavailable on the market.

The invention has for further object to provide lubricating compositions which have lubricity, anti-wear and extreme-pressure properties quite sufficient for satisfying the present requirements.

Generally speaking, the sulfurized compositions of the invention are obtained by sulfurizing ester compositions comprising a major proportion of one or more unsaturated esters forrned by total esterification of:

a. one or more saturated or unsaturated aliphatic monoor di-carboxyiic acids containing, for example, from 4 to 22 carbon atoms, with b. one or more ethylenically unsaturated aliphatic mono-hydric alcohols.

When considering the definition of the unsaturated esters of the invention, the aliphatic carboxylic acid may particularly consist of:

a saturated chain monocarboxylic acid such as for example, 2-ethyl hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid or iso-decanoic acid;

a monocarboxylic acid having an unsaturated chain such as, for example, oleic acid (9-octadeceneoic), linoleic acid (9,12-octadecadiene-oic) or undecenoic acid,

or a mixture of saturated and unsaturated monocarboxylic acids, such as certain mixtures of fatty acids of animal origin, such as the fatty acids of tal- 2 low, or of vegetal origin, such as those obtained from soja-oil, colza-oil or by tall-oil distillation.

The aliphatic carboxylic acid may also consist of:

a dicarboxylic acid having a saturated straight chain, such as adipic acid, azelaic acid, sebacic acid or dodecane/dioic acid; or a dicarboxylic acid having a saturated branched chain such as, trimethyladipic acids or isononadecane/dioic acid,

or a dicarboxylic acid having an unsaturated straight chain, such as maleic or fumaric acid, or having an unsaturated branched-chain, such as alkenyl/succinic acid, for example tetrapropenyl/succinic acid.

The ethylenically unsaturated aliphatic monohydric alcohol usually comprises a straight or preferably branched aliphatic chain of at least 8 carbon atoms with at least one ethylenic unsaturation.

Among the aliphatic monohydric alcohols which can be used, we contemplate, according to a first embodiment of our invention, those which result from condensing formaldehyde with an aliphatic mono-olefin usually containing from 8 to 20 carbon atoms, thus containing, as a rule, from 9 to 21 carbon atoms.

In that case, the unsaturated aliphatic alcohol is preferably obtained from an aliphatic mono-olefin able to react with formaldehyde in the conditions of the Prins reaction with high yield. In this respect, it is advantageous to make use of an olefin having its ethylenic unsaturation at the end of the chain and linked to a completely substituted carbon atom.

Among the most suitable olefins, we can mention the following: isobutene dimer, propylene trimer, propyiene tetramer, isobutene trimer and isobutene tetramet.

The condensation of formaldehyde on the olefin is usually carried out at a temperature of from to l60C, preferably in an autoclave, and in acetic, preferably anhydrous medium, for example during 6 to 20 hours. We preferably use for one mole of olefin:

from 0.8 to 1.5 mole of formaldehyde, preferably in the form of poloxymethylene, and

from to 350 ml of glacial acetic acid or a mixture of glacial acetic acid and acetic anhydride.

It may be advantageous to proceed at a moderate temperature of from 80 to C, while using a catalyst, for example para-toluene/sulfonic acid or phosphoric acid, in a small amount, for example from 0.1 to 1% b.w. with respect to the reactants.

Conversely, it is preferable to avoid temperatures higher than C, which would result in a cracking of the olefin and/or its condensation products to a certain extent, and also in the coloration of the reaction products.

The mixture obtained at the end of the reaction is distilled, optionally under vacuum, in order to remove the acetic solvent and, if necessary, all or part of the unreacted olefin fraction. This fraction, which may amount to 20-45 of the olefin fed, may be recycled. The distillation residue is then washed with hot water, preferably alkali-containing water, so as to eliminate the residues of formaldehyde and acid, then saponified for example by means of an excess of sodium hydroxide dissolved in methanol. The saponification is carried out at reflux, for example for 0.5 to 2 hours, and is continued until the product, after washing and drying, has a saponification number of approximately zero. This product will be referred to as olefin condensation product".

TABLE I Starting olefin Hydroxyl number Unsaturation (mg KOH per gram) per 100 g) Propylene trimer 330 370 0.64 0.60 Propylene tetramer 24S 280 0.5l 0.48 lsobutene dimer 345 390 0.70 0.66 lsobutene \etramer l95 220 0.39 036 According to a second embodiment of the invention, the ethylenically unsaturated aliphatic alcohol is selected among those resulting from selectively reducing a branched a,B-unsaturated aliphatic aldehyde, itself resulting from the aldolization-crotonization of one or more lower saturated aliphatic aldehydes of the formula:

where R is a straight alkyl radical and X is either a straight alkyl radical or a hydrogen atom, preferably a methyl radical or a hydrogen atom, and containing, for example, from 4 to 12 carbon atoms. The unsaturated aliphatic alcohol thus usually contains from 8 to 24 carbon atoms.

As examples of aldehydes of the general formula (I), which can be used as starting materials for the aldolization-crotonization reaction, the following may be mentioned:

n-butanal, n-pentanal, n-hexanal, n-heptanal, n-octanal, n-decanal, and the aldehydes obtained according to the "oxo" process from straight a-olefins containing, for example, from 3 to 11 carbon atoms (the oxo process is well known: it consists of reacting, at high temperature and in the presence of a catalyst, a mixture of carbon monoxide and hydrogen with an olefin).

The latter aldehydes consist of mixtures of compounds of the formula (I) where X is a hydrogen atom or a methyl radical (in these mixtures, the straight aldehydes are in major proportion, usually about 75 The aldolization-crotonization of aldehydes is alo well-known. It is disclosed, for example, in Organic Reactions, John Wiley and Sons, New York (1968), volume l6. it consists in condensing an aldehyde on itself or on another aldehyde, usually in the presence of a basic catalyst, and dehydrating the alcohol formed.

By aldolization-crotonization of the saturated aldehydes of the formula (I) above, there are obtained branched a,B-unsaturated aliphatic aldehydes (containing, for example, from 8 to 24 carbon atoms), from which are obtained, by selective reduction, the unsaturated alcohols employed for preparing the unsaturated esters of the invention.

The selective reduction of these a, ,B-unsaturated aldehydes to unsaturated alcohols may be achieved according to any conventional method. It is thus possible to make use of a reducing compound such as, for example, aluminium-lithium hydride, aluminium iso-propoxide, potassium or sodium borohydride. However, for economic reasons, molecular hydrogen is preferably employed, in the presence of a convenient catalyst, such as, for example, partially poisoned platinum oxide, partially poisoned platinum-on-carbon, lead-inhibited ruthenium or osmium or a carbon or alumina carrier, the latter two catalysts giving the best results.

The catalytic reduction with hydrogen may be carried under relatively mild conditions, for example at a temperature of about l60C under a hydrogen pressure of about 30-120 kglcm Preferably we proceed in an autoclave provided with an efficient stirring system. At the end of the reaction, the catalyst is separated and recovered for example, by filtration. lt must be noted that a solvent is not necessary, as far as the reduction of the a,B-unsaturated aldehydes used according to the invention is concerned, although it may facilitate filtering of the reaction product and consequently recovering the catalyst. There is used, for example, an alcohol such as isopropanol. After the filtering of the reaction product and an optional vaporization of the solvent, there is obtained an unsaturated alcohol or a mixture of unsaturated alcohols which can be used for manufacturing the compositions of unsaturated esters according to the invention.

Depending on the starting saturated aldehyde (or mixture of aldehydes), the resulting unsaturated alcohol (or mixture of alcohols) has a variable hydroxyl number (for example about 16 to 44 milligrams of potassium hydroxide per gram of product) and a variable unsaturation degree (for example about 0.28 to 0.76 ethylenic double bond per I00 g of product).

The total esterification of the aliphatic carboxylic acid or acid mixture with the unsaturated aliphatic monohydric alcohol may be carried out according to any convenient method.

For example, we may proceed at reflux of a solvent such as, for example, benzene, toluene or a xylene, with azeotropic removal of the formed water, and catalyze the reaction by means of a small amount, for example 0.l2% b.w., of an acid such as para-toluene/sulfonic acid. After evaporation of the solvent, the esterification product may be purified, for example by passing it on activated earth.

According to other ways of manufacturing the unsaturated ester compositions, we may use, instead of the monoand di-carboxylic acids themselves, some of their functional derivatives, such as their halides (for example their chlorides), anhydrides or lower alkyl esters.

When preparing compositions of unsaturated esters, without departing from the invention, the ethylenically unsaturated aliphatic mono-hydric alcohol(s) may be used in admixture with a minor proportion of one or more saturated aliphatic alcohols, particularly for adjusting the unsaturation degree of the feeding mixture of alcohols to be subjected to esterification and consequently the unsaturation degree of the ester compositions resulting therefrom. These saturated aliphatic alcohols, which contain, for example, from 6 to 20 carbon atoms, may consist of alcohols having a saturated aliphatic straight chain, such as, for example, hexanol, heptanol, octanol, nonanol, decanol, dodecanol or eicosanol, or of alcohols having a saturated aliphatic branched chain such as, for example, Z-ethyl hexanol or alcohols obtained by oxo synthesis from olefins, for

example iso-nonanol, iso-decanol and iso-tridecanol.

They can be used in a proportion of from to 30 by weight of the total weight of the alcohols subjected to esterification, depending on the desired unsaturation degree of the resulting ester composition.

The sulfur-containing compositions of the invention result from the sulfurization of ester compositions such as hereinbefore described, particularly those having an unsaturation degree of from about 0.20 to about 0.55 ethylenic bond per 100 grams.

These compositions may be sulfurized, for example up to a content of about 6 to by weight of sulfur, depending on the case, according to any convenient technique. For example, the following technique may be used:

From 7 to parts b.w. of elemental sulfur and from 0.5 to 2 parts b.w. of zinc oxide are added to 100 parts b.w. of an ester composition, such as hereinbefore defined. The stirred mixture is heated in a first step at a temperature of from 145 to 175C, for example for 5-10 hours, in an inert atmosphere. After this first treatment, the temperature is raised in a second step to 180l-88C, for example during 2-4 hours. During this second step, a minor proportion of the fixed sulfur, for example about 10 of the total sulfur content of the charge, is removed in the form of hydrogen sulfide. There is thus obtained, after filtering, a sulfurized product according to the invention.

The following technique may also be used:

7-20 parts by weight of elemental sulfur and 0.5-4 parts b.w. of a secondary aliphatic amine, for example dicyclohexylarnine, are added to 100 parts by weight of the ester composition. The stirred mixture is heated at a temperature of from 130 to 160C, for example during 5-10 hours, under an atmosphere which is inert with respect to the reactants. After filtering, the sulfurized product of the invention is obtained.

It may be advantageous to conduct the sulfurization reaction, for example, according to one of the hereinbefore described methods, with an ester composition diluted with a minor proportion, for example 1040 b.w., of a substrate such as a light mineral oil, corresponding for example to the SAE grade 10 W or 5 W or a synthetic oil, for example iso-decyl adipate or 2-ethyl hexyl maleate.

Finally, if the extreme-pressure properties of the obtained sulfurized product are to be specifically enhanced, it is convenient to have it react, for example for 2-8 hours at a temperature of 90'l20C, with a lower proportion, for example 0.2-0.6 by weight of phosphorus sesquisulfide (P S The sulfurized products of the invention are used as additives for lubricants, either for mineral oils or for synthetic oils. As a rule, they are added to the lubricating bases in an amount of from 0.5 to 10 by weight 6 tially improved anti-wear and extreme-pressure properties, without noticeably modifying the pour point. The resulting lubricating compositions also have an extremely low corrosivity with respect to usual metals, particularly copper.

The following examples illustrate the invention and must not be considered as limitative thereof. The unsaturation numbers given in these examples have been determined by the Brown method consisting of a selective catalytic hydrogenation of the ethylenic bonds on palladium.

EXAMPLE I 252.5 g (2 moles) of propylene trimer, 72 g (2.4 moles) of paraformaldehyde and 500 ml of glacial acetic acid are introduced into a stirred autoclave. The mixture is heated at 120C for 10 hours and strongly stirred. Acetic acid and a portion (about g) of the unreacted olefin are separated by distillation. The residue is washed with hot water (80C) and then treated at C with a 10 N solution of sodium hydroxide in a mixture of water and methanol. After careful washing with water, there are recovered 205 g of olefin condensation product in the form of an oily liquid of straw yellow colour, having the following characteristics:

Hydroxyl number 341 mg of potassium hydroxide per gram.

Unsaturation: 0.62 ethylenic bond per 100 g.

164 g (one hydroxyl equivalent) of this olefin condensation product, 282 g (1 mole) of oleic acid, 2 g of paratoluene/sulfonic acid and ml of benzene are poured into a 2 liter flask. The mixture is heated at smooth reflux. Any formed water is continuously collected by decantation in a Dean and Stark apparatus. During esterification, temperature remains at l20-l30C. After 9 hours, 17.6 g of water collected and heating is discontinued. After water-washing and benzene-evaporating, 425 g of unsaturated ester composition ester composition are obtained.

200 g of this unsaturated ester composition, 26 g of sulfur and 2 g of zinc oxide are introduced into a 500 ml reactor provided with stirring means. The mixture is heated and stirred under nitrogen for 7 hours at C, then 3 hours at C. After filtering, 222 g of Additive l are obtained, said additive having the following characteristics:

viscosity at 989C: 21 cst pour point: -15C sulfur content 10.8 by weight EXAMPLES 2-6 Various olefin condensation products have been pre pared according to the technique of Example 1.

The nature and amounts of reactants, as well as the and preferably from 1 to 5 by weight of the lubricat- 55 nature and characteristics of the obtained condensaing base. They confer to the latter base very substantion products are summarized in Table ll below:

TABLE ll Olefin condensation Olefin Para product Ex. Nature Amount formaldehyde weight hydroxyl unsatu- (g) (m (g) (mls) (g) number(l) filliOfKZ) 2 isobutene dimer 448.8 4 144 4.8 396 362 0.68 3 propylene 673 4 144 4.8 558 255 0.49

tetramer 4 as in Example 3 5 as in Example 3 6 as in Example I (l)in mg of potassium hydroxide per gram (2}in number of ethylenic bonds per I00 grams According to the same technique as in Example 1, each of the so obtained olefin condensation products is used to esterify a carboxylic acid, in order to form the corresponding unsaturated ester compositions. The nature and amounts of reactants, as well as the obtained amount of unsaturated ester composition are indicated in Table 111 below:

b.w. (11.5 g) of a osmium catalyst on an alumina carrier. The temperature is raised to 100C, the hydrogen pressure to 70 kg/cm and the stirring started.

When no more hydrogen absorption is observed, the reaction mixture is cooled, diluted with 250 ml of isopropanol and filtered, in order to separate the catalyst therefrom. After vaporization of iso-propanol, 231 g of 200 g of each of the so obtained unsaturated ester compositions have been sulfurized in the conditions of Example 1. Table IV gives the proportions of employed sulfur and zinc oxide, the amount of obtained sulfurized product and the characteristicss thereof.

a. 75 ml of a 1 N sodium hydroxide solution in water are heated at 80C in a 500 ml reaction vessel provided with a mechanical stirrer, a bulb cooler maintained at 5C and a 350 ml bromine funnel. 252 g of n-heptanal are introduced dropwise in l h mn through the bromine funnel. After heptanal addition, the temperature is raised so as to obtain a gentle reflux, which is maintained for 1 h 30 run. The reaction mixture is then cooled and carefully washed with water, in the presence of hexane, up to neutrality. After hexane evaporation, 230 g of a,B-unsaturated C aldehyde are obtained.

The so obtained B-unsaturated aldehyde is placed in a 500 ml stirred autoclave, in the presence of 5 unsaturated alcohol are collected, said alcohol having the following characteristics:

Hydroxyl number: 264 mg KOH per gram Unsaturation number: 0.47 per g.

b. 212 g (1 hydroxyl equivalent) of this unsaturated alcohol, 73 g (1 acid equivalent) of adipic acid, 1 g of para-toluene/sulfonic acid and 100 ml of benzene are introduced into an 1 liter flask. The mixture is heated at gentle reflux. The formed water is continuously collected by decantation in a Dean and Stark system. During the esterification, the temperature remains at -130C. Afier 8 hours, 17.8 g of water have been collected and heating is discontinued. After waterwashing and benzene-vaporizing, 265 g of unsaturated ester are obtained, said ester having an unsaturation number of 0.37 per 100 g.

c. 200 g of this unsaturated ester, 25 g of sulfur and 4 g of dicyclohexylamine are introduced into a 500 ml reactor provided with a mechanical stirrer. The mixture is heated and stirred under nitrogen at C for 6 hours. 223 g of Additive VII are obtained, said Additive being so characterized:

Viscosity at 989C: 32 est Pour point: l4C

Sulfur content: 10.6 b.w.

EXAMPLES 8-14 the obtained unsaturated alcohols are summarized in Table V below:

"During n-hutanal addition. the temperature must not exceed 90C. Atter complete introduction of n-butanal, the vessel is heated under gentle reflux.

"The mixture, obtained from a cut of straight u-olefins C. C by Otto-reaction. contains by mole. n- Z-methyl r 20%; nr Z-methyl hexane-25096; n-octanal 2-methyl heptanal:30%.

The mixture, obtained from a cut of straight cr-olefins C. C by axe-reaction. contains by mole: n-nonanal Z-methyl octanal:30%; n-decanal 2-methyl nonanal:70%.

The hydroxyl number if expressed in mg of potassium hydroxide per gram of product.

The unsaturation number is expressed as the number of ethylenic double bonds In order to evaluate the anti-wear and extreme-pressure qualities of the products obtained according to Examples 1-14, each of them has been dissolved in a proportion of 3 b.w. in a base oil (A) and the resulting compositions have been tested with test machines.

Base oil (A) is a mixture by equal parts of 150 neutral mineral oil and a 450 Neutral mineral oil.

The test machines are, on the one hand, the fourballs machine (E.P.Tester) for determining the Load- Wear Index (L.W.I) according to ASTM standard D- 2783-71 and, on the other hand, the machine FZG for determining the damage level (i.e. the seizing level noted from 1 to 12) and the specific wear (i.e. the average slope of the wear curve before seizing, expressed in mg/horse power-hour) according to the German standard DIN 51 354 of January 1970, with gear weighing.

Table VIII gives the results obtained with compositions containing Additives I to XIV. By way of comparison, there are given the results obtained with base oil (A) alone and with the same base oil containing 3 by weight of sulfurized spermaceti oil.

per 100 3'0! product. Composition L.W.l. Damage Specific b. According to the same technique as in Example 25 g) e e a 7(b), each of the so-obtained unsaturated alcohols is used to esterify a carboxylic acid to form the corree o (A) I 6 32 sponding unsaturated esters. The nature and amounts tgfif gg 45,2 0 42 of reactants and also the amount of obtained unsatu- (A) 3% b.w. of Additivel 60.7 11 0.ll6 (A) 3% b.w. of Additive 11 58.9 12 0109 rated ester are gwen m Table (A) 3% b.w. of Additive 111 54.0 0.112

TABLE VI unsat.alcohol saturated alc. carboxylic acid ester Ex. weight OH Eq. nature amount nature amount (g) Uns.

(g) (g) (OH Eq.) acid (2) 8b) 212 l none none none dodecal l 307 0.32

nedioic 9b) I484 0.7 2-Lhyl 39 0.3 oleic 282 1 450 0.32

hexanol 10b) 128 l none none none isonona I64 I 2 7 l 0.34

decanedioic 1 lb) 2l7 l none none none azelaic 94 l 291 0.3l 12b) 173.6 0.8 n-hepta- 23.2 0.2 adipic 73 1 2 0.29

nol 13b) 190 0.7 mixture 39.9 0.3 Tall oil 288 1 520 0.41

C,C,,C", fatty acids Mb) 212 1 none none none nona- 158.2 l 351 0.26

noic

(The mixture, whose hydroxyl number is 42] mg of KOH/g, by mole: ri- 21%; n- 35%; n-decanolz 44% (2)The eitiuii is as the b of L, double bonds per 100 g of product:

c. 200 g of each of the so-obtained unsaturated esters have been sulfurized in the conditions of Example 7(0). (A) 3% W 532 0122 A) 3% b.w. of Additive V 63.l l2 0.1l7 Following Table VII gives: the amounts of employed (A) 3% 1m, f Additive w 600 H 0109 sulfur and dicyclohexylamine, the amount of obtained (2): g: 2 02223110: 1 1 8.135 sulfurized product and the characteristics thereof. 2 6 3% 1: 3 ist: IX H :135 (A) 3% b.w. of Additive x 60.l 12 0.121 TABLE (A) 3% b.w. of Additive x1 50.5 10 0.130 Di (A) 3% b.w. of Additive x11 59.3 12 0.091 A) 3% b.w. of Additive x111 58.7 11 0.114 S cyclo- Resulting sulfurized product EX. (g) hexyb name wt. viscm pour S (A) 3% b.w. of Addltive XIV 56.6 l0 0.]33

amine (g) sity (g) 989C point b.w. 60

(est) (0C) The improvement of the anti wear and extreme-pres- 22 4 Addit.VIII 219 37 l2 3.9 ure to efljes of the as l 9c) 35 4 Addiux 232 41 -11 13.9 th d d f t i theddlimn of 10c) 28 4 Add x 225 39 11.2 e su rize pro ucts o e invention, 15 quite re- };e) g 4 Aggitgi: 32 g? 12 3-3 markable. It is substantially better than when using sulc) 4 A it. 5 l3c) 26 4 Addit.Xll| 224 as 7 l0.8 fumed spermaFetl Me) 23 4 Addit.XIV 220 22 -9 9.0 What we claim is:

1. A sulfur-containing composition obtained by sulfurizing an ester composition having a degree of unsatu- 1 l ration of 0.20-0.55 double bonds per 100 grams, said ester being formed by total esterification of:

a. at least one aliphatic hydrocarbyl monoor di-carboxylic acid means with b. at least one aliphatic hydrocarbyl monohydric alcohol means consisting essentially of 70-l00% by weight of at least one branched aliphatic hydrocarbyl unsaturated monohydric alcohol having about I ethylenic unsaturation and containing at least 8 carbon atoms and -30% by weight of at least one saturated aliphatic hydrocarbyl monohydric alcohol.

2. A composition according to claim 1, wherein the monoor di-carboxylic acid means contains 4-22 carbon atoms.

3. A composition according to claim 1, wherein said monohydric alcohol means consists essentially of about 100% of the branched unsaturated alcohol.

4. A composition according to claim 1, wherein the ester composition results from totally esterifying:

a. at least one aliphatic hydrocarbyl monoor dicarboxylic acid means with b. 70-90% by weight of the at least one branched aliphatic hydrocarbyl unsaturated monohydric alcohol and -30% by weight of the at least one saturated aliphatic hydrocarbyl monohydric alcohol.

5. A composition according to claim 1, wherein the saturated aliphatic monohydric alcohol contains from 6 to carbon atoms.

6. A composition according to claim 1, wherein the aliphatic monoor di-carboxylic acid means comprises a halide, an anhydride or a lower alkyl ester.

7. A composition according to claim 1, wherein the sulfurization degree is 6-15 by weight of sulfur.

8. A composition according to claim 7, wherein the sulfurization is carried out by heating the ester composition in the presence of a convenient amount of elemental sulfur, so as to obtain the desired sulfurization degree and the obtained product is filtered.

9. A composition according to claim 1, wherein the sulfurization is carried out on the ester composition previously diluted in a diluent comprising isodecyl adipate or 2-ethylhexyl maleate.

10. A composition according to claim 9, wherein the diluent amounts to 10-40 by weight of the ester composition.

11. A composition according to claim 1, wherein the ethylenically, unsaturated aliphatic monohydric alcohol results from condensing formaldehyde with a branched monoolefin of 8-20 carbon atoms, said alcohol itself containing 9-21 carbon atoms.

12. A composition according to claim 11, wherein the branched aliphatic monoolefin is isobutene dimer, propylene trimer, propylene tetramer, isobutene trimer or isobutene tetramer.

13. A composition according to claim 1, wherein the aliphatic hydrocarbyl ethylenically unsaturated monohydric alcohol contains 8-24 carbon atoms and results from selectively reducing a branched a,B-unsaturated aliphatic aldehyde, itself resulting from the aldolization-crotonization of at least one saturated aliphatic aldehyde of 4-12 carbon atoms and of the general formula:

in which R is a straight alkyl radical and X is selected from the hydrogen atom and the straight alkyl radicals.

14. A composition according to claim 13, wherein X is a hydrogen atom or a methyl radical in the formula of the saturated aliphatic aldehyde.

15. A composition according to claim 7, wherein the monohydric alcohol means consists essentially of about 100% of the at least one unsaturated alcohol.

16. A composition according to claim 7, wherein the ester composition results from the complete esterification of:

a. At least one aliphatic hydrocarbyl monoor dicarboxylic acid means with b, -90% by weight of the at least one aliphatic hydrocarbyl ethylenically unsaturated monohydric alcohol and 10-30% by weight of the at least one saturated aliphatic hydrocarbyl monohydric alcohol.

17. A composition according to claim 16, wherein the saturated aliphatic monohydric alcohol contains from 6 to 20 carbon atoms.

18. A composition according to claim 17, wherein the aliphatic monoor di-carboxylic acid means comprises a halide, an anhydride or a lower alkyl ester.

19. A composition according to claim 3, wherein the sulfurization degree is 6-15% by weight of sulfur.

20. A composition according to claim 19, wherein the sulfurization is carried out by heating the ester composition in the presence of a convenient amount of elemental sulfur, so as to obtain the desired sulfurization degree and the obtained product is filtered.

21. A composition according to claim 20, wherein the sulfurization is carried out on the ester composition previously diluted in a diluent comprising isodecyl adipate or Z-ethylhexyl maleate.

22. A composition according to claim 7, wherein the ethylenically unsaturated aliphatic monohydric alcohol results from condensing formaldehyde with a branched aliphatic mono-olefin of 8-20 carbon atoms, said alcohol itself containing 9-2] carbon atoms.

23. A composition according to claim 22, wherein the branched aliphatic monoolefin is isobutene dimer, propylene trimer, propylene tetramer, isobutene trimer or isobutene tetramer.

24. A composition according to claim 20, wherein the aliphatic hydrocarbyl ethylenically unsaturated monohydric alcohol contains 4-8 carbon atoms and results from selectively reducing a branched 01,3- unsaturated aliphatic aldehyde, itself resulting from the aldolization-crotonization of at least one saturated aliphatic aldehyde of 4-12 carbon atoms and of the general formula:

in which R is a straight alkyl radical and X is selected from the hydrogen atom and the straight alkyl radicals.

25. A composition according to claim 24, wherein X is a hydrogen atom or a methyl radical in the formula of the saturated aliphatic aldehyde. 

1. A SULFUR-CONTAINING COMPOSITION OBTAINED BY SULURIZING AN ESTER COMPOSITION HAVING A DEREE OF UNSATURATION OF 0.02-0.55 DOUBLE BONDS PER 100 GRAMS, SAID ESTER BEING FORMED BY TOTAL ESTERIFICATION OF: A. AT LEAST ONE ALIPHATIC HYDROCARBYL MONO-OR DI-CARBOXYLIC ACID MEANS WITH B. AT LEAST ONE ALIPHATIC HYDROCARBYL MONOHYDRIC ALCOHOL MEANS CONSISTING ESSENTIALLY OF 70-100% BY WEIGHT OF AT LEAST ONE BRANCHED ALIPHATIC HYDROCARBYL UNSATURATED MONOHYDRIC ALCOHOL HAVING ABOUT 1 ETHYLENIC UNSATURATION AND CONTAINING AT LEAST 8 CARBON ATOMS AND 0-30% BY WEIGHT OF AT LEAST ONE SATURATED ALIPHATIC HYDROCARBYL MONOHYDRIC ALCOHOL.
 2. A composition according to claim 1, wherein the mono- or di-carboxylic acid means contains 4-22 carbon atoms.
 3. A composition according to claim 1, wherein said monohydric alcohol means consists essentially of about 100% of the branched unsaturated alcohol.
 4. A composition according to claim 1, wherein the ester composition results from totally esterifying: a. at least one aliphatic hydrocarbyl mono- or dicarboxylic acid means with b. 70-90% by weight of the at least one branched aliphatic hydrocarbyl unsaturated monohydric alcohol and 10-30% by weight of the at least one saturated aliphatic hydrocarbyl monohydric alcohol.
 5. A composition according to claim 1, wherein the saturated aliphatic monohydric alcohol contains from 6 to 20 carbon atoms.
 6. A composition according to claim 1, wherein the aliphatic mono- or di-carboxylic acid means comprises a halide, an anhydride or a lower alkyl ester.
 7. A composition according to claim 1, wherein the sulfurization degree is 6-15 % by weight of sulfur.
 8. A composition according to claim 7, wherein the sulfurization is carried out by heating the ester composition in the presence of a convenient amount of elemental sulfur, so as to obtain the desired sulfurization degree and the obtained product is filtered.
 9. A composition according to claim 1, wherein the sulfurization is carried out on the ester composition previously diluted in a diluent comprising isodecyl adipate or 2-ethylhexyl maleate.
 10. A composition according to claim 9, wherein the diluent amounts to 10-40 % by weight of the ester composition.
 11. A composition according to claim 1, wherein the ethylenically, unsaturated aliphatic monohydric alcohol results from condensing formaldehyde with a branched monoolefin of 8-20 carbon atoms, said alcohol itself containing 9-21 carbon atoms.
 12. A composition acCording to claim 11, wherein the branched aliphatic monoolefin is isobutene dimer, propylene trimer, propylene tetramer, isobutene trimer or isobutene tetramer.
 13. A composition according to claim 1, wherein the aliphatic hydrocarbyl ethylenically unsaturated monohydric alcohol contains 8-24 carbon atoms and results from selectively reducing a branched Alpha , Beta -unsaturated aliphatic aldehyde, itself resulting from the aldolization-crotonization of at least one saturated aliphatic aldehyde of 4-12 carbon atoms and of the general formula:
 14. A composition according to claim 13, wherein X is a hydrogen atom or a methyl radical in the formula of the saturated aliphatic aldehyde.
 15. A composition according to claim 7, wherein the monohydric alcohol means consists essentially of about 100% of the at least one unsaturated alcohol.
 16. A composition according to claim 7, wherein the ester composition results from the complete esterification of: a. At least one aliphatic hydrocarbyl mono- or dicarboxylic acid means with b. 70-90% by weight of the at least one aliphatic hydrocarbyl ethylenically unsaturated monohydric alcohol and 10-30% by weight of the at least one saturated aliphatic hydrocarbyl monohydric alcohol.
 17. A composition according to claim 16, wherein the saturated aliphatic monohydric alcohol contains from 6 to 20 carbon atoms.
 18. A composition according to claim 17, wherein the aliphatic mono- or di-carboxylic acid means comprises a halide, an anhydride or a lower alkyl ester.
 19. A composition according to claim 3, wherein the sulfurization degree is 6-15% by weight of sulfur.
 20. A composition according to claim 19, wherein the sulfurization is carried out by heating the ester composition in the presence of a convenient amount of elemental sulfur, so as to obtain the desired sulfurization degree and the obtained product is filtered.
 21. A composition according to claim 20, wherein the sulfurization is carried out on the ester composition previously diluted in a diluent comprising isodecyl adipate or 2-ethylhexyl maleate.
 22. A composition according to claim 7, wherein the ethylenically unsaturated aliphatic monohydric alcohol results from condensing formaldehyde with a branched aliphatic mono-olefin of 8-20 carbon atoms, said alcohol itself containing 9-21 carbon atoms.
 23. A composition according to claim 22, wherein the branched aliphatic monoolefin is isobutene dimer, propylene trimer, propylene tetramer, isobutene trimer or isobutene tetramer.
 24. A composition according to claim 20, wherein the aliphatic hydrocarbyl ethylenically unsaturated monohydric alcohol contains 4-8 carbon atoms and results from selectively reducing a branched Alpha , Beta -unsaturated aliphatic aldehyde, itself resulting from the aldolization-crotonization of at least one saturated aliphatic aldehyde of 4-12 carbon atoms and of the general formula:
 25. A composition according to claim 24, wherein X is a hydrogen atom or a methyl radical in the formula of the saturated aliphatic aldehyde. 